Current methods used for manufacturing a chemically adsorbed multilayer film include cumulation (built-up) methods, mentioned, for example, in page 851 of the sixth volume of Langmuir (K. Ogawa et al., Langmuir, 6, 851 (1990)) and page 201 of the one hundred first volume of Journal of Colloid Interface Science (J. Gun et al., Journal of Colloid Interface Science, 101, 201 (1984)). The cumulation (built-up) methods include repetitions of the following process:
forming a monomolecular film by a dehydrochlorination reaction between a chlorosilyl group of a chemical adsorbent, which is a linear molecule having the chlorosilyl group at one end and a double bond at the other end, with a group on the surface of the substrate such as a hydroxyl group; PA1 creating reactive hydrogen atoms by modifying the double bond either by treating it with oxidizing agents such as potassium permanganate or irradiating it with an electron beam. PA1 forming a chemically adsorbed film by contacting a substrate surface with a chemical adsorbent which has one or more halogen atoms and functional groups selected from the groups in the following Formulas 1!-5! and a cyano group on the substrate surface; EQU --A.sub.1 X.sub.m Formula 1! PA1 reacting the alkaline metal composition with a chemical adsorption composition that includes a functional group, selected from the groups shown in the above formulas 1!-5!, a carbonyl, aldehyde, carboxyl, acyl, amide, or ester group.
Reactive hydrogen atoms also can be made by replacing the double bond with an amino group by irradiating a polymer film having the double bond with an electron beam in a nitrogen atmosphere, thereby forming a multilayer film.
However, the above-noted method of using an electron beam is problematic in that it requires an expensive large-scale apparatus. Also, a film is likely to be disrupted due to the subtle changes in radiation intensity of an electron beam. Moreover, severe risks are involved in the operation.
The method of treating with oxidizing agents, on the other hand, has a problem in that an unsaturated bond is not likely to be oxidized when the unsaturated bond is located on the surface of the monomolecular film (that is, the end of a monomolecular chemical adsorbent). Due to the usage of strong oxidizing agents, moreover, there is a problem in that the Si--C bond is likely to be broken.